I too am trying to use the Western Digital Data Lifeguard Diagnostic disc on a Dell Inspiron 1525 and am also experiencing the black screen problem.
The ISO is correctly burnt (I work as a professional computer technician) and the machine boots from the disc.
Caldera DR-DOS loads and executes autoexec.bat. When DLGDIAG5.EXE loads the screen clears and then simply remains black. Repeated keypresses eventually produce a beep from the laptop as the keyboard buffer is filled.
If I use F8 to bypass loading autoexec.bat I can get to the command prompt, at which point the same symptoms occur when I manually execute DLGDIAG5.EXE
I have tried both AHCI and ATA mode for the hard disk in the BIOS, both of which produce the same results. Another search result for this problem suggests disabling RAID mode, but this model does not support such a thing.
I am confident the disk is bad, and want to return it under warranty. However, I did want to dot all the i’s and cross all the t’s where the RMA procedure is concerned, and run a diagnostic before returning the bad disk.
I cannot run the Windows version of the diag as the disk is so badly corrupted that Windows will no longer boot.
If anyone has any bright ideas I’d welcome them. Thanks.